Environmental Engineering Reference
In-Depth Information
chlorofluorocarbons (CFCs)
A group of chemicals
containing chlorine, fluorine and carbon, used
in refrigeration and air conditioning systems and
in the production of polymer foams. Inert at
surface temperature and pressure, they become
unstable in the
stratosphere,
breaking down to
release chlorine which initiates a catalytic
chemical reaction leading to the destruction of
ozone
.
chloroform
A volatile liquid solvent which contributes
to
ozone depletion
through the release of chlorine.
chlorophyll
A green pigment in plants which makes
photosynthesis
possible through its ability to
absorb solar energy.
circumpolar vortex
A band of strong winds circling
the poles in the upper atmosphere. The vortex is
mainly a winter phenomenon and best developed
around the South Pole.
Clear Air Legislation
Various laws, acts and ordinances
designed to bring about the reduction of
atmospheric pollution.
climate
The combination or aggregate of weather
conditions experienced in a particular area. It
includes both averages and extremes as measured
over an extended period of time.
Climate Impact Assessment Program (CIAP)
A
programme commissioned by the US Department
of Transportation in the mid-1970s to study the
effects of
supersonic transports (SSTs)
on the
ozone
layer.
Climatic Optimum
Period of major warming during
the immediate post-glacial period between 5,000
and 7,000 years ago.
coal gasification
The heating or cooking of coal—
sometimes in place—to release volatile gases such
as
methane,
a cleaner, more efficient fuel than the
coal itself.
coal liquefaction
The conversion of coal into a liquid,
petroleum-type fuel by a combination of heating
and the use of solvents and
catalysts
.
Concorde
The most successful of the two types of
supersonic transport
built in the 1970s
condensation nuclei
Small particles in the
atmosphere, of natural or anthropogenic origin,
around which water vapour condenses to form
liquid droplets.
continental tropical air mass (cT)
An air mass
originating over tropical to sub-tropical continental
areas, and therefore hot and dry.
contingent drought
A type of drought characterized
by irregular and variable precipitation in areas
which normally have an adequate supply of
moisture to meet crop needs.
convective circulation
Circulation initiated by surface
heating which causes the vertical movement of
heated air. After cooling the air ultimately returns
to the surface to complete the circulation.
cosmic rays
High-energy radiation reaching the earth
from outer space.
coupled models
Models which combine two or more
simulations of elements in the earth/atmosphere
system.
Carbon cycle models,
for example, have
been combined with oceanic and atmospheric
circulation models in the search for a better
understanding of global warming.
coupled ocean/atmosphere climate models
The most
common combination in coupled models. The main
problem with these models is the difference in time
scales over which atmospheric and oceanic
phenomena develop and respond to change.
Because of the relatively slow response time of the
oceanic circulation, the oceanic element in most
coupled models is much less comprehensive than
the atmospheric element.
crumb structure
The combination of individual soil
particles into loose aggregates or crumbs.
cyclone
An atmospheric low pressure system,
generally circular in shape, with the air-flow
counter-clockwise in the Northern Hemisphere
and clockwise in the Southern Hemisphere and
converging towards the centre of the system.
Commonly used to refer to intense tropical
storms in the Indian Ocean which are the
equivalent of Atlantic hurricanes or Pacific
typhoons.
D
deforestation
The clearing of forested areas as part
of a commercial forestry enterprise or for some
other economic purpose such as the expansion
of settlement or the development of agriculture.
degradation induced drought
Drought promoted by
environmental degradation usually initiated by
human activity which disrupts the regional energy
and water balances.
demography
(The study of) statistics on human
populations, including such elements as growth
rate, age and sex, and their effects on socio-
economic and environmental conditions.
